Intramedullary interlocking fixation device for the distal radius

ABSTRACT

Methods and devices for treating fractures in or adjacent the wrist and distal forearm employ an intramedullary interlocking fixation rod (i.e, it interlocks the distal and proximal fracture fragments together) to stabilize the skeletal structure in a manner which can inhibit the amount of collapse or loss in skeletal length exhibited by a patient with a distal radius fracture.

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/668,941, filed Sep. 22, 2000, the contents of which arehereby incorporated by reference as recited in full herein.

FIELD OF THE INVENTION

[0002] This invention relates to devices and methods for treating distalradius fractures.

BACKGROUND OF THE INVENTION

[0003] Distal radius fractures are among the most common type of bonefracture of the upper extremities. The distal radius fracture is oftencalled a “Colles” fracture (named after a 19^(th) Century Britishsurgeon who described the fracture). The Colles fracture is associatedwith a fracture of a distal tip or distal end portion of the radius.

[0004] Distal radius fractures are, unfortunately, most common in theelderly segment of the population. This is because the elderly tend toexhibit some degree of bone density loss or osteoporotic conditionmaking their bones more susceptible to injury. Indeed, just asosteoporosis is known to affect women more often and more severely thanmen, distal radius fractures are much more common in females than males,typically on the order of about 20:1. Distal radius fractures generallyoccur as a result of a fall, because the patient tends to brace for thefall by outstretching the hand which then fractures upon impact, at thedistal radius at or adjacent the wrist.

[0005] As shown in FIGS. 1 and 2, the distal radius fracture is suchthat the major fracture line 15 associated with this type of injurygenerally occurs just above or proximal to the articular joint surface11 of the distal radius at the wrist about the metaphysis 12. As shownin FIGS. 1 and 2, one common distal radius fracture type separates theshaft 13 of the radius 10 from the distal end portion of the bone. Thatis, the fracture line 15 defines a first major bone fragment 18 which islocated above the fracture line 15 (the distal side) proximate thearticular joint surface 11 and extends substantially medially(laterally) across the radius 10 in the metaphysis region. Although notshown, the fracture may also produce smaller bone fragments or splintersalong the fracture line. Further, the distal end portion of the radiusmay be present as multiple (vertically and/or horizontally oriented)fragments disrupting the articular joint surface itself. This lattertype of Colles fracture is known as a comminuted intraarticular fracture(not shown).

[0006]FIG. 1 illustrates the fracture line 15 in the radius 10 as asubstantially horizontal line which produces an upper or distal fracturefragment 18 as a substantially unitary fragment. Similarly, FIG. 2illustrates a fracture line 15 in the radius 10 which is offset from ahorizontal axis.

[0007] Distal radius fractures can be difficult to treat, particularlyin the older osteoporotic patient. Conventionally, this type of fracturehas been treated by a closed (non-surgical) reduction and application ofa splint (such as a plaster compression dressing) or a cast (typicallycircular plaster or fiberglass). Unfortunately, primarily because of thepatient's osteoporosis, during the healing process, and despite thesplint/cast immobilization, the fracture fragments can settle,potentially causing a collapse at the fracture line in the distalradius. FIG. 2 illustrates a loss of radial inclination (in degrees) anda shortened length in the skeletal length line (shown with respect to aneutral length line “L”) which can occur after a fracture in the distalradius. That is, even healed, these types of fractures may causeshortening or collapse of the bone structure relative to the originalskeletal length line. This, in turn, can result in deformity and pain.

[0008] Treatment options for a collapsed distal radius fracture arerelatively limited. The primary conventional treatments include the useof devices which can be characterized as either external fixationdevices or internal fixation devices. External fixation devices arethose that stabilize a fracture through the use of percutaneous pinswhich typically affix one or more bone portions to an external(anchoring or stabilizing) device. Internal fixation devices are thosedevices which are configured to reside entirely within the subject(internal to the body). Percutaneous pins can be used alone, withoutanchoring devices, for fixation of Colles type fractures. The use ofexternal devices has conventionally been thought to be particularlyindicated in cases of bone loss to preserve skeletal length as noted,for example, in U.S. Pat. No. 5,571,103 to Bailey at col. 1, lines35-43. However, such devices can be bulky, cumbersome, and or invasiveto the user or patient. Further, the external fixation devices may notbe suitable for use in soft osteoporotic bone.

[0009] In view of the foregoing, there remains a need for improveddistal radius fracture treatment devices and techniques.

SUMMARY OF THE INVENTION

[0010] In a preferred embodiment, the present invention provides methodsand devices for treating fractures in or adjacent the wrist and distalforearm. The present invention is particularly useful for stabilizingand treating distal radius fractures of a patient. The devices andmethods of the present invention employs an intramedullary interlockingfixation rod (i.e, it interlocks the distal and proximal fracturefragments together) to stabilize the skeletal structure in a mannerwhich can inhibit the amount of collapse or loss in skeletal lengthexhibited by a patient with a distal radius fracture. The devices andmethods of the present invention may be especially useful for treatingdistal radius fractures in subjects with osteoporosis.

[0011] One aspect of the invention is a method for treating a distalradius fracture of a patient comprising the use of an internal fixationrod. As noted above, the radius anatomically has an articular jointsurface, a metaphysis region, a shaft portion and a medullary canalassociated therewith. The distal radius fracture has a fracture linewhich divides the radius into a distal fracture fragment portion and aproximal fracture fragment portion. The distal fragment portion includesthe distal end of the radius proximate the articular joint surface, andthe distal portion of the fracture has a width thereacross. The methodcomprises the steps of: (a) installing an elongated rod having opposingproximal and distal portions into the medullary canal of the patientsuch that the proximal portion of the rod resides above the fractureline (closer to the elbow) and the distal portion of the rod residesbelow the fracture line (closer to the hand); (b) securing a distalfixation member to the elongated rod and into the distal end portion ofthe radius at a location which is below the fracture line such that thedistal fixation member extends internal of the patient substantiallylaterally across a portion of the width of the distal fracture fragment;and (c) anchoring the elongated rod inside the medullary canal of theradius at a location which is above (distal to) the fracture line.

[0012] Another aspect of the present invention is an internal fixationdevice for treating or repairing distal radius fractures having afracture line forming distal and proximal fracture fragments. The radiusis anatomically configured with a distal articular joint surface, ametaphysis region, a shaft, and a medullary canal. The anatomic positionof the hand is palm forward or front such that the medial orientation isnext to the body (fifth finger or ulna side of hand) and the lateralorientation is away from the body (thumb or radial side). Generallystated, the distal portion of the radius has a width which extendsacross (a major portion of) the arm from the medial side to the lateralside. The device includes an elongated fixation rod having opposingproximal and distal portions. The distal portion includes a head with alaterally extending distal aperture formed therein, and the proximalportion comprises at least one proximal aperture formed therein. Theelongated fixation rod proximal portion is sized and configured suchthat, in position, it resides in the shaft inside a portion of themedullary canal of the radius of a patient. The device also includes adistal fixation member configured to enter the distal aperture andattach to the rod and the distal fracture fragment to hold the distalportion of the rod to the distal fracture fragment. The device furtherincludes at least one proximal fixation member, a respective one foreach of the at least one proximal apertures. The proximal fixationmember is configured to secure the lower portion of the fixation rod tothe radius at a position which is distal to the fracture line. Inposition, the elongated fixation rod is configured to reside within theradius, and the distal fixation member and the at least one proximalfixation member are configured to reside internal of the body of thepatient.

[0013] In a preferred embodiment, the elongated fixation rod has acurvilinear profile. The curvilinear profile includes a distal curveportion at the distal portion of the device. The distal curve portion isadapted to accommodate the radial styloid region of the radius proximatethe articular joint surface. The rod can also be provided as a pluralityof segments matable or attachable. In one embodiment an intermediatesegment can be provided in different lengths to allow for the adjustmentof length according to a patient's anatomical considerations. Of course,the rod can be a unitary body provided in a number of standard sizespreferably statistically representative of the treatment population.

[0014] The foregoing and other objects and aspects of the presentinvention are explained in detail in the specification set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is an anterior-posterior view of a distal radius fractureillustrating a fracture line proximate the articular joint surface.

[0016]FIG. 2 is an anterior-posterior view of a distal radius fracturesimilar to that shown in FIG. 1. This figure illustrates analternatively configured fracture line proximate the articular jointsurface.

[0017]FIG. 3A is an anterior-posterior view of an intramedullaryfixation rod attached to the radius for treating a distal radiusfracture according to an embodiment of the present invention.

[0018]FIG. 3B is an exploded view of the distal fixation attachmentmember shown inserted into the fixation rod in FIG. 3A according to oneembodiment of the present invention.

[0019]FIG. 4 is a front schematic view of the distal fixation rod ofFIG. 3A in position as an internal fixation device held within the bodyof the patient according to one embodiment of the present invention.

[0020]FIG. 5A is a lateral view of an intramedullary rod configured tointerlock or affix the bone fragments of a distal radius fractureaccording to one embodiment of the present invention.

[0021]FIG. 5B is a cross-sectional view of the rod shown in FIG. 5Ataken along line 5B-5B.

[0022]FIG. 6 is a perspective view of an intramedullary fixation deviceaccording to one embodiment of the present invention.

[0023]FIG. 7 is a side view (shown oriented anterior to posterior) of analternate embodiment of an intramedullary system according to thepresent invention.

[0024]FIG. 8 is a side view (shown oriented anterior to posterior) ofanother embodiment of an intramedullary system according to the presentinvention.

[0025]FIGS. 9A is a front anterior-posterior view of an alternateembodiment of a distal fixation rod according to the present invention.

[0026]FIG. 9B is an exploded view of the linked or multi-segment rodshown in FIG. 9A.

[0027]FIG. 9C is a front view of a set of intermediate rod segmentsaccording to an embodiment of the present invention.

[0028]FIG. 10 is a schematic side view of an intramedullary system withan external detachable positioning guide according to an embodiment ofthe present invention.

[0029]FIG. 11 is a block diagram of the steps of treating a distalradius fracture according to one embodiment of the present invention.

[0030]FIG. 12 is perspective view of the arm of a patient illustrating asigmoid or longitudinal incision over the radial styloid area.

[0031]FIG. 13 is an enlarged schematic view of the incision site in thepatient shown in FIG. 12 to illustrate preparation of the site forpositioning intramedullary fixation rods for distal radius fracturesaccording to an embodiment of the present invention.

[0032]FIG. 14 is an enlarged schematic view of the incision site shownin FIG. 13 illustrating that a small bone window may be made or formedinto the radius such that it extends across the fracture site accordingto the present invention.

[0033]FIGS. 15A is an anterior-posterior view of the bone window shownin FIG. 14.

[0034]FIG. 15B is a schematic view of the prepared bone site shown inFIG. 15A illustrating the use of a sound or broach instrument which issized and configured to be inserted into the intramedullary canal of theradius to determine size and/or open or prepare the canal to receive afixation rod according to an embodiment of the present invention.

[0035]FIG. 16 is a top anterior-posterior view of an intramedullaryfixation rod assembled to a rod driver and screw attachment guideaccording to one embodiment of the present invention.

[0036]FIG. 17 is a side (lateral) view of the device shown in FIG. 16.

[0037]FIG. 18 is a side of the device shown in FIGS. 16 and 17 showingthe device in position in the patient.

[0038]FIG. 19 is a top anterior-posterior view of the device shown inposition in FIG. 18.

[0039]FIG. 20 is a schematic view of the fixation rod in position in thesubject according to an embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0040] The present invention will now be described more fullyhereinafter with reference to the accompanying figures, in whichpreferred embodiments of the invention are shown. This invention may,however, be embodied in many different forms and should not be construedas limited to the embodiments set forth herein. Like numbers refer tolike elements throughout. In the figures, certain layers, regions, orcomponents may be exaggerated for clarity.

[0041] As shown in FIG. 3A, in a preferred embodiment, theintramedullary fixation device 25 includes an elongated axiallyextending rod 26 with a distal portion 27 and a proximal portion 28. Thedevice 25 also includes a distal fixation member 30 and at least oneproximal fixation member 35 (shown as two proximal fixation members 35a, 35 b). The rod 26 includes a head 26 h at the distal end portion 27of the rod 26. A distal aperture 30 a is formed into the head 26 h ofthe distal portion such that it extends across the width of the rod 26.

[0042] As shown, the distal fixation member 30 is configured to enterand extend through and beyond the distal aperture 30 a to engage withthe distal fracture fragment 18 and secure the rod 26 and the distalfracture fragment 18 theretogether. Preferably, the distal fixationmember 30 is sized to extend across a major portion of the width of thedistal fracture fragment 18. More preferably, the distal fixation member30 is sized with a length which is sufficient to extend acrosssubstantially all of the fracture fragment 18 so as to provide supportfor the radial, center, and ulna aspects of the distal fracture fragment18 (the ulna aspect being the part of the fracture fragment adjacent orproximate the ulna 14 while the radial aspect being the portion of thefracture fragment on the opposing side of the view shown in FIG. 3A andthe center aspect being the portion in between).

[0043]FIG. 3B illustrates the distal fixation member 30 apart from therod 26. The distal fixation member 30 can be configured as any suitableattachment means to secure the distal fracture fragment 18 to the rod26, while also providing lateral structural reinforcement. For example,but not limited to, the attachment means can be one or more of a pin,nail, threaded or partially threaded member such as a screw, or acombination of the above. FIG. 3B illustrates the distal fixation member30 as having, in serial order, from one end to the other, a head portion30 h, a threaded portion 30 _(th), and a pin portion 30 p.

[0044] In one embodiment, as shown in FIG. 3A, the head of the distalfixation member 30 h extends beyond the edge of the body of the rod 26.However, as schematically shown in FIG. 7, the aperture 25 a can beconfigured (such as with a countersunk or recessed portion configuredwith a depth sufficient to receive the head 30 h therein) such that uponassembly, the distal fixation member head 30 h is substantially flush orrecessed with the outer contour or profile of the rod 26. FIG. 3A alsoillustrates that, in position in the patient, the distal fixation member30 is preferably configured to directly abut the outer surface of therod 26. FIG. 6 is a perspective view of one embodiment of theintramedullary fixation device 25. This embodiment shows that the rod 26is configured as a unitary body with a recess to receive the head 30 hof the distal fixation member 30.

[0045] In a preferred embodiment, the rod 26 is configured with aprofile 26 p which is curvilinear when viewed from theanterior-posterior view, as shown, for example, in FIGS. 3A and 4. Asshown, the proximal portion of the rod 28 is substantially linear and isconfigured to axially extend within the medullary canal of the patientin the radial shaft. As the rod 26 approaches the metaphysis region (12,FIG. 1) it gradually curves from the substantially linear axialextending portion so as to position the distal end 27 e of the rod 26proximate the radial styloid region of the distal radius. Preferably,the rod 26 is configured to follow the contour line of the radius as ittransitions from the proximal portion 28 having a substantially linearcontour in the shaft region to the distal portion 27 which has acurvilinear or slight arcuately contoured shape proximate the metaphysisregion.

[0046]FIGS. 3A and 4 also illustrate that the head 26 h of the rod 26 ispreferably configured with a body which has an increased perimeter orarea size with respect to the proximal 28 portion of the rod 26. It isalso preferred that the distal end of the head 26 h be beveled orinclined 27 i. As shown, the tip or end of the head 26 h slopesdownwardly from the side surface adjacent the radial portion toward theulna aspect of the fracture fragment 18.

[0047] It is additionally preferred that the distal aperture 30 a beformed in the rod 26 such that it allows the distal fixation member 30to extend therethrough and reside at a position which is angularlyoffset from the axial axis. As shown in FIG. 3A, the axial axis iscoincident with the centerline of the proximal portion of the rod(indicated by the letter “a” in FIG. 3A). Preferably, the distalfixation member 30 extends at a position which is less than about ninetydegrees, and preferably between about 10 degrees to less than about 90degrees, away from the axial axis, such that it is approximately in-linewith the articular surface.

[0048] In this embodiment, the head 26 h of the rod 26 can buttress thedistal radius region and increase the structural effectiveness of therod. Thus, together with the proper positioning of the distal portion 27of the rod 26 in the distal radius and/or the medial extension of thedistal fixation member 30, the head 26 h, can reinforce or positivelyaffect the structural integrity of the device to help support the radialstyloid region of the distal fracture fragment.

[0049] Referring again to FIG. 3A and FIG. 4, at least one, andpreferably two or more, proximal fixation members 35 are used to securethe rod 26 to the shaft region 13 of the radius 10 at the lower orproximal portion of the rod 26. FIG. 3A illustrates the use of twosimilarly sized proximal fixation members 35 a, 35 b, respectively,while FIG. 4 illustrates the use of one 35. Preferably, as shown in FIG.5A, the proximal fixation members 35 a, 35 b are respective self-tappingscrews positioned on the rod 26 such that they are proximate to eachother. However, pins, nails, or other attachment means (as well asnumbers and positioning of same) can also be used as will be appreciatedby one of skill in the art. It will be appreciated, by those of skill inthe art, that the proximal fixation members 35 and correspondingapertures 25 a are primarily used to inhibit shortening of the skeletalstructure. As shown in FIG. 5A, the proximal fixation member 35transversely extends in serial order, through a portion of the radiusshaft, through a corresponding proximal receiving aperture 25 a formedin the rod 26, and then into an opposing portion of the radius shaft tothereby secure or locate and hold the proximal portion of the rod 25relative to the radius, the proximal fixation member having a length andopposing ends sized and configured accordingly 36, 38.

[0050]FIG. 4 schematically illustrates the preferred post-operativeposition of the intramedullary fixation device 25 in the patient. Thatis, post-operatively in position in the patient, the rod 26 and distaland proximal fixation members 30, 35 are held within the body of thesubject such that the device 25 is an internal fixation device and isdevoid of externally located coupling or fixation members.

[0051] As shown in FIG. 4, the rod 26 is installed into the medullarycanal of the patient such that the distal portion 27 of the rod 26resides distal to the fracture line 15 (but substantially within thedistal radius, preferably so as to reside proximal to the articularjoint surface 11) and the bottom or proximal portion 28 of the rod 26extends through and resides proximal to the fracture line 15. The distalfixation member 30 is secured to the rod 26 and to the distal endportion of the radius at a location which is distal to the fracture line15 in the metaphysis region of the distal radius. As is also shown, thedistal fixation member 30 extends (to reside internal of the body of thepatient) substantially transversely across a portion of the width of thedistal fracture fragment 18. The device 25 may not be preferred for usewith comminuted distal radius fractures.

[0052] In position, the rod 26 is configured such that it also extendsthrough a portion of the medullary canal to terminate therein in theshaft region 13 of the radius 10 (FIG. 1) (at a location which isproximally spaced away from the fracture line 15). The proximal portion28 of the rod 26 is anchored to the radius so as to reside inside themedullary canal of the radius. The proximal portion 28 of the rod 26 isfixed in position relative to the shaft of the radius by the use of atleast one pin, screw, or the like, as discussed above. As is also notedabove, it is more preferred that two (and potentially three or more) toprovide increased structural stability so as to inhibit the propensityof the rod 26 to toggle or move distally with the distal fragment.

[0053]FIG. 4 also illustrates that the proximal end of the rod 28 e maybe configured with a reduced cross-sectional size or tapered perimeterrelative to the portion of the rod 26 thereabove to allow for ease ofinsertion into the patient. Preferably, as shown, the proximal end ofthe device 28 e is substantially pointed.

[0054]FIG. 5A illustrates the rod 26 with a length “L”, a width “W” anda thickness “T”. It is envisioned that the rod 26 be provided or be madeavailable for use in a plurality of lengths and widths so that theclinician can select the appropriate dimensions according to theparticular anatomical needs of the patient. Preferably, for the distalradius fracture, the length of the rod 26 is between about 2-5 incheslong, and more preferably between about 2.5 inches-4.0 inches long. Itis also preferred that the width of the rod 26 be provided in anarrangement of incremental sizes. It is thought that suitable widths maybe between about 2-8 mm in width and more preferably between about(2.5-4 mm) in width.

[0055] As shown in FIG. 5B, the rod 26 is held in the medullary canal ofthe radius of the patient. The lower or proximal portion 28 of the rod26 is preferably held substantially centrally in the shaft portion 13 ofthe radius 10. In one embodiment, the cross sectional shape of the rod26 is rectangular. The rod 26 can be configured with othercross-sectional shapes, such as, but not limited to, circular, oval,square, triangular, and hexagon. It is also preferred that in designswith sharp edges, that the edges be radiused (“break edges”) to reducethe likelihood of stress fractures in the rod 26 (or in the boneadjacent the rod). Further, the distal portion 27 of the rod 26 may havea different cross-sectional shape and configuration from the proximalportion 28 of the rod 26. For example, the proximal portion 28 of therod 26 may have a circular shape with the addition of a ribbed portionon one side to inhibit rotation once in the intramedullary canal in theradius of the patient, while the distal portion 27 of the rod 26 canhave an oval or rectangular shape (not shown).

[0056]FIG. 7 illustrates another embodiment of an intramedullaryfixation device 25′ according to the present invention. In thisembodiment, the rod 26 is configured as first and second attachablesegments or links 127, 128. As shown, the distal segment 127 of the rod26 is configured with the head of the rod 26 h while the proximalportion 128 is again configured to reside in the medullary canal of theradius shaft. The two segments 127, 128 are configured to align and matetogether to define the rod 26. As shown in FIG. 7, a linking screw 120is inserted into a threaded aperture 120 a that it spans the first andsecond segments 127, 128 when aligned. Of course, other attachment meansor segment link configurations can also be used, such as, but notlimited to, bayonet type fittings, friction fit or threaded matablefemale/male components, and the like.

[0057]FIG. 8 illustrates another embodiment of an intramedullaryfixation device 25″ for the radius according to the present invention.In this embodiment, the rod 26 includes a proximal extension 28ext. Asshown, the proximal extension 28ext is tapered adjacent the proximal endportion 28 of the rod 26. The extension 28ext is configured to reside ina more proximal portion of the radius shaft (away from the hand andcloser to the elbow). This embodiment may also be used in the absence ofa distal radius fracture to treat proximal radius fractures. FIG. 8 alsoillustrates that the distal fixation member 30 is oriented at about 45degrees with respect to the axial axis. In any event, this configurationcan allow for additional support in the shaft region of the radius(i.e., more proximal “purchase”).

[0058]FIG. 9A illustrates a rod 26 having a body with multiple segmentsor links 127′, 129, 128′. As shown, in this embodiment, the rod 26 isdefined by three segments, the distal segment 127′, an intermediatesegment 129, and a proximal segment 128′. FIG. 9B illustrates that, inthis embodiment, the distal segment 127′ includes a protrusion 127 p′while the upper portion of the intermediate segment 129 includes arecess 129 r configured and sized to matably and/or securely receive theprotrusion 127 p′ therein. Similarly, the proximal segment 128′ includesa recess 128 r′ formed therein configured to receive the intermediatesegment protrusion 129 p therein. Preferably, the segments 127′, 129,128′ are sized and configured to be held together by a frictional fit ofthe interlocking or mating components, however, a biocompatible adhesivecan also be used, as desired. Other attaching means can also be used tosecure the segments together as will be appreciated by those of skill inthe art. For example, the protrusion 127 p′ can be threaded andconfigured to threadably engage with a threaded recess 129 r formed inthe upper portion of the intermediate segment 129. Similarly, theproximal recess 128 r′ can be threaded and configured to threadablyengage with the intermediate segment 129 p protrusion (which can beconfigured as a correspondingly configured male threaded component).

[0059] As shown in FIG. 9C, the intermediate segment 129 can be providedin an assortment of lengths to allow the rod 26 to be adjusted to adesired length according to the anatomical considerations of thepatient. Alternatively, the intermediate segment 129 can be a pluralityof similarly sized or different, incrementally sized segments. In thisway, the distal and proximal segments 127′, 128′ can be provided asstandardized-length components with the intermediate segment 129providing an adjustable length. Thus, the clinician can custom fit therod 26 at the use site. That is, the clinician can assess the patientand then determine the appropriate number or size of intermediatesegments 129 to be used dependent on the length desired. This custom fitdoes not require the use of a preformed rod or a special order rod.Rather, the fit can be carried out at the clinic, use, or installationsite (proximate in time or contemporaneous with the treatment) to fitthe number and size components together according to the needs of thepatient. Alternatively, the distal and/or proximal segments 127′, 128′can also (or alternatively) be configured as or provided in differentlengths.

[0060]FIG. 10 illustrates the use of an insertion or positioning guide150 affixed to the distal end portion 27 of the rod 26 to allow for easeof insertion and placement into the patient. As shown, the guide 150includes an axially (or longitudinally) extending arm 151 which isconfigured to reside external of the body of the patient when the rod 26is inserted into the intramedullary canal. As is also shown, the guidearm 151 includes a visual locating means or visual indicia 153, 155which correspond to the proximal fixation apertures 25 a ₁, 25 a ₂ tomark or identify the location of the internal apertures when the rod 26is in a desired position in the patient. This allows the physician to beable to insert the proximal fixation members 35 a, 35 b in the properlocation, aligned with the proximal apertures on the rod 26 held insidethe patient.

[0061] As shown, the visual indicia 153, 155 is preferably provided aslaterally extending drill guides 153, 155 which act to support a drillas it enters the patient and allows the drill to be inserted therein andguided to the desired location to provide bores into the bone onopposing sides of the rod 26 that are aligned with the rod proximalfixation apertures 25 a ₁, 25 a ₂.

[0062] Referring to FIG. 12, generally described, to position theintramedullary fixation rod 26 into the patient, an incision is made,such as a sigmoid or longitudinal incision over the radial styloidregion of the patient's arm (adjacent to the base of the thumb). Asshown in FIG. 13, dissection is carried down to the interval between thefirst and second dorsal compartments. Care should be taken so as not toinjure the branches of the dorsal radial nerve. A small area of exposedbone is present between the first and second compartments (typicallycovered only by periosteum). As shown in FIGS. 14 and 15A, a small bonewindow 16 is preferably formed or made into the radius in this area. Itmay be appropriate to elevate the sheaths of the first and second dorsalcompartments to facilitate adequate exposure for the bone window 16.Although shown as a substantially rectangular bone window, other shapesmay also be used to provide access to the fracture region.

[0063] As shown in FIG. 15B, a finder, sound, or broach-like device 175can be used prior to inserting the fixation rod 26 into the patient. Thedevice 175 is preferably semi-flexible to follow the contour of thecanal in the radius. The device 175 can be inserted through the bonewindow 16 and about the fracture region and used to determine the sizeand length of the intramedullary canal and/or to open the canal to asize suitable for receiving the fixation rod 26. The sounds areavailable in length-and width calibrated sizes to help determine a sizeand length suitable for the fixation rod 26 according to the particularpatient's intramedullary canal structure. As such, the device 175 canbore out or ream and/or define a desired entry and insertion passagewayfor the device 25, 25′, 25″ in advance of an actual installation intothe patient. A fluoroscopic evaluation technique can be used tovisualize the insertion of the device 175 and can help determine if thecanal needs to be enlarged with a reamer or if a insertion path needs tobe formed or shaped.

[0064] After the appropriate size and length fixation rod 26 isselected, the rod can be attached to an insertion guide device 150,150′. FIG. 10 illustrates one embodiment of a guide 150. As shown, anapplicator/handle or driver 150 is attached to the rod 26 into thedistal aperture 30 a). The handle or driver 150 then allows thephysician to insert and guide the rod 26 into the desired location inthe medullary canal in the radius. Once the head 26 h of the rod 26 ispositioned below the articular joint surface, in its desired location inthe distal radius, the proximal fixation members 35 (35 a, 35 b) areready for insertion. Preferably, a small incision (or two) is made atthe proximal site of the radius. A drill or driver is inserted into thelocator or drill guide holder 152 to align the entry of the proximalfixation member about the proximal aperture 25 and then force thethreaded proximal fixation member(s) 35 (35 a, 35 b) through the bone onthe first (dorsal) side of the shaft of the radius, through the rodaperture 25 a ₁ (25 a ₂) and into the bone on the opposing (volar) sideof the radial shaft. Preferably, the proximal fixation member 35 (35 a,35 b) extends through both sides of the bone. Next, the guide 150 shownin FIG. 10 is removed and the distal fixation member 30 is then insertedinto the rod 26 through the distal aperture 30 a and attached to thedistal radius (FIG. 4). Preferably, the distal fixation member 30 isinserted into the radius at the fracture site or at an exposed site(created by removing a portion of the bone) to allow the head 30 h (FIG.3A) of the distal fixation member 30 to be inserted into the rod 26 suchthat it rests directly against the body of the rod 26 (eitherprotruding, flush, recessed therewith) and extends into the distalfracture fragment 18.

[0065]FIGS. 16 and 17 illustrate an additional embodiment of aninsertion guide 150′. In this embodiment, the device 150′ includes a roddriver 250 and an interlocking screw attachment guide 151′. Once theproper rod size is identified, the rod 26 is attached to the rod driver250. The rod driver 250 is attached to the fixation rod 26 via thedistal aperture in the head of the rod 26 and an associated attachmentmember (shown as a screw 30 a) and the interlocking screw attachmentguide 151′ is attached to the rod driver 250. As for the other guideembodiment described above, the interlocking screw attachment guide 151′provides a screw guide alignment means such as screw or pin portals 153,155 to facilitate proper orientation and location of the proximal screwsor pins into the patient and into the shaft 25 of the fixation rod 26.Thus, in this embodiment, the span of the screw attachment guide 151′ isconfigured to provide the proper alignment position relative to the roddriver 250.

[0066] As shown in FIGS. 18 and 19, the rod driver 250 of the insertionguide 150′ is used to direct the rod 26 into the intramedullary canal ofthe patient. The rod driver 250 allows a physician to direct thefixation rod 26 into the radius through the bone window 16. The positionof the rod and the reduction of the fracture can be verified by afluoroscopy unit. Once the rod 26 is in position, a small incision canbe made so that the proximal attachment guides 153, 155 can be insertedtherein. Traction may be appropriate to reduce the fracture at thistime. The proximal attachment members 35 a, 35 b can then be insertedinto the radius after the region has been drilled and/or tapped. Again,the proper positioning of the proximal attachment members 35 a, 35 b,can be verified by the fluoroscopy unit. The interlocking screwattachment guide 151′ can then be removed from the patient and the roddriver 250. The rod driver 250 can be detached from the fixation rod 26and the distal fixation member 30 can be inserted into the distalfragment and the fixation rod 26 as shown in FIG. 20.

[0067] Routine closure is performed on the incision sites and then,preferably, a long arm cast is applied to the patient. The typicalhealing process is about six weeks, during which time it is preferredthat the treatment area be protected from undue stress and activity.

[0068] A rod according to the present invention can be formed from anumber of suitable biocompatible materials including titanium, stainlesssteel, and cobalt chrome. Because the radius is not a weight bearingextremity, strength is not as important in this type of fixation rod asit might be in other fixation rod applications.

[0069] Surface coatings may also be used as appropriate. For example, asthe device 25, 25′, 25″ chronically resides in the body, surface orother treatments may also be applied to, or integrated into, the rod 26and/or the fixation members 30, 35 to achieve one or more of increasedlubricity, low coefficient of friction (each for easier insertion) aswell as increased tissue biocompatibility such as resistance tomicrobial growth and/or configured to reduce the incidence ofinflammation or infection during healing. In one embodiment, the rod 26comprises a material, at least on its exposed surfaces, which caninhibit the growth of undesirable microbial organisms. Preferably, therod is coated with a biocompatible antimicrobial solution or coatingwhich can inhibit the growth of bacteria, yeast, mold, and fungus. Onesuitable material may be the antimicrobial silver zeolite based productavailable from HealthShield Technologies LLC of Wakefield, Mass. Anotheralternative is a Photolink® Infection Resistance antimicrobial coatingor a hemocompatible coating from SurModics, Inc. of Eden Prairie, Minn.The coating may also include other bioactive ingredients (with orwithout the antimicrobial coating), such as antibiotics, and the like.One product is identified as LubriLAST™ lubricious coatings from AST ofBillerica, Mass.

[0070] In addition to, or alternatively, a rod according to the presentinvention can be configured with a biocompatible lubricant orlow-friction material to help reduce any discomfort associated with theinsertion of the device into the body. Coatings which may be appropriateinclude coatings which promote lubricity, and wettability. For example,a hydrophilic coating which is applied as a thin (on the order of about0.5-50 microns thick) layer which is chemically bonded with UV lightover the external surface of the rod 26. One such product is ahydrophilic polymer identified as Hydrolene® available from SurModics,Inc., of Eden Prairie, Minn. Other similar products are also availablefrom the same source. Still further, the rod 26 can be configured notonly to provide the lubricious coating but to also include bioactiveingredients configured to provide sustained release of antibiotics,antimicrobial, and anti-restenosis agents, identified as LubriiLast™from AST as noted above.

[0071]FIG. 11 illustrates the steps of a method for treating a fracturein the radius of a patient according to one embodiment of the presentinvention. An elongated axially extending rod is inserted into theintramedullary canal of the patient (Block 210). Proximal fixationmembers are then secured to the rod to hold the rod in theintramedullary canal attached to the proximately located bone in theradius shaft (Block 220). A distal fixation member is inserted into adistal portion of the rod such that it extends substantially medially ortransversely across a distal portion of the radius (Block 230). A bonewindow may be formed into the radius to define an entry point for therod (typically the window is formed into a small area of exposed bonewhich is present between the first and second compartments and coveredonly by periosteum) in the styloid region adjacent the two bonefragments.

[0072] The internal intramedullary radius fixation devices andassociated treatment methods of the instant invention can provideimproved or alternative treatment options over those conventionallyavailable. The devices and methods of the instant invention may inhibitthe collapse in the skeletal structure along the fracture fragmentregion and may be useful for the osteoporotic patient. The devices ofthe instant invention can also provide increased structural integrityand/or strength when in position in the distal radius fracture fragment.

[0073] The foregoing is illustrative of the present invention and is notto be construed as limiting thereof. Although a few exemplaryembodiments of this invention have been described, those skilled in theart will readily appreciate that many modifications are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of this invention. Accordingly, all suchmodifications are intended to be included within the scope of thisinvention as defined in the claims. In the claims, means-plus-functionclauses, if used, are intended to cover the structures described hereinas performing the recited function and not only structural equivalentsbut also equivalent structures. Therefore, it is to be understood thatthe foregoing is illustrative of the present invention and is not to beconstrued as limited to the specific embodiments disclosed, and thatmodifications to the disclosed embodiments, as well as otherembodiments, are intended to be included within the scope of theappended claims. The invention is defined by the following claims, withequivalents of the claims to be included therein.

That which is claimed is:
 1. A method for treating a distal radiusfracture of a patient comprising the use of an internal fixation rod,the radius anatomically having an articular joint surface, a metaphysisregion, a shaft portion and a medullary canal associated therewith, thedistal radius fracture having a fracture line which divides the radiusinto a distal fracture fragment portion and a proximal fracture fragmentportion, the distal fragment portion including the distal end of theradius proximate the articular joint surface, the distal portion of thefracture having a width thereacross, said method comprising the stepsof: implanting an internal fixation device comprising an elongatedfixation member, a distal fixation member, and at least one proximalfixation member into a subject to treat a distal radius fracture, sothat a proximal portion of the elongated fixation member resides in theshaft inside the medullary canal of the radius of a patient, wherein adistal portion of the elongated fixation member distal portion has ahead with a laterally extending distal aperture formed therein;inserting the distal fixation member into the laterally extendingaperture in the head of the elongated fixation member so that the distalfixation member attaches to the elongate member and the distal fracturefragment to hold the distal portion of the elongate fixation member tothe distal fracture fragment, wherein the distal fixation member has alength and is sized and configured so that, in position, it laterallyextends through the head of the elongated fixation member in the distalaperture and beyond the perimeter of the elongate fixation member toreside across at least a major portion of the radius in the metaphysisregion, so, that, in position, the elongated fixation member isconfigured and sized to reside within the radius such that both theopposing distal and proximal portions reside within the natural boundsof the radius of the patient; and attaching the at least one proximalfixation member to the elongated fixation member to anchor the elongatedfixation member inside the medullary canal of the radius at a locationwhich is below the fracture.
 2. A method according to claim 1, whereinsaid attaching step includes the step of inserting, in serial order, atleast one proximal fixation member into a first side of the shaft of theradius, into the elongated rod in the intramedullary canal, and theninto the opposing side of the shaft of the radius.
 3. A method accordingto claim 2, wherein the at least one proximal fixation member is two. 4.A method according to claim 1, wherein the elongated fixation memberincludes a respective one aperture formed therein for each of said atleast one proximal fixation members.
 5. A method according to claim 4,wherein each proximal aperture is unthreaded and the proximal fixationmembers are configured to threadably attach to the radius shaft.
 6. Amethod according to claim 4, further comprising: attaching an externalpositioning guide onto a distal portion of the elongated fixation membersuch that the guide extends above the radius external of the patient'sskin to visually indicate the position of the at least one proximalaperture in the elongated fixation member as it resides in the medullarycanal of the patient; and removing the external positioning guide aftersaid step of securing said at least one proximal fixation member to theelongated fixation member and the radius.
 7. A method according to claim1, wherein the elongated fixation member is configured, when viewed froman anterior-posterior direction, such that the elongated fixation membersubstantially linearly extends along the proximal portion thereof andthen transitions to take on a curvilinear profile adjacent the distalportion of the rod.
 8. A method according to claim 7, wherein said upperdistal end portion of the elongate fixation member has an increasedcross-sectional area relative to the lower proximal portion.
 9. A methodaccording to claim 1, wherein said upper distal end portion of theelongate fixation member has a head which is beveled.
 10. A methodaccording to claim 1, wherein said securing the distal fixation memberto the elongated fixation member is carried out such that the distalfixation member extends substantially medially across a major portion ofthe width of the distal fracture fragment but within the bounds of theoutermost natural pre-injury perimeter of the radius bone.
 11. A methodaccording to claim 10, wherein said distal fixation member is sized andconfigured so that, in position, it extends across substantially theentire width of the distal fracture fragment from the radial to ulnarregions to provide support for the central and ulnar aspect of thedistal radius fragment.
 12. A method according to claim 10, wherein thedistal fixation member angularly extends between about 10-90 degreesaway from the axial direction defined by a line drawn through the centerof the proximal portion of the elongated fixation member.
 13. A methodaccording to claim 1, wherein at least a portion of said elongatedfixation member has a cross section which is substantially rectangular.14. A method according to claim 1, further comprising the step ofproviding the elongated fixation member in an assortment of incrementalsizes ranging from between about 2.5-4.5 inches long.
 15. A methodaccording to claim 1, wherein the distal fixation member is sized andconfigured with a medial extension length that is sufficient to extendacross at least a major portion of the width of the distal fracturefragment in the metaphysis region of the distal radius without extendingbeyond the natural pre-injury perimeter of the radius.
 16. A methodaccording to claim 1, wherein the elongated fixation member isconfigured with linkable segments.
 17. A method according to claim 1,wherein the elongated fixation member has a unitary body.
 18. A methodaccording to claim 16, wherein the distal end portion of the elongatedfixation member is matably attached to an intermediate portion of theelongated fixation member.
 19. A method according to claim 16, whereinthe elongated fixation member includes at least three matable segments,a distal end segment, a proximal end segment, and an intermediate lengthadjustable segment configured to attach said distal and proximal endsegments together.
 20. A method according to claim 19, wherein theintermediate segment is provided in an assortment of lengths to adjustto the desired length of the elongated fixation member for customizedsizing at a use or treatment point.
 21. A method according to claim 20,wherein the intermediate segment is a plurality of linkable similarsized segments for adjusting the desired length of the rod to reflectthe patient's anatomical needs.
 22. A method according to claim 21,further comprising the step of selecting a desired length of theintermediate segment to correspond with the anatomy of the patient andattaching the intermediate segment to the distal end and proximal endsegments.
 23. An internal fixation device for treating or repairingdistal radius fractures having a fracture line forming distal andproximal fracture fragments, the radius anatomically configured with adistal articular joint surface, a metaphysis region, a shaft, and amedullary canal, the distal portion of the radius having a width whichextends from a radial region to a central and ulnar region, said devicecomprising: an elongated fixation member having opposing distal andproximal portions, said distal portion including a head with a laterallyextending distal aperture formed therein, said proximal portioncomprising at least one proximal aperture formed therein, wherein saidelongated fixation member proximal portion is sized and configured suchthat, in position, it resides in the shaft inside the medullary canal ofthe radius of a patient; a distal fixation member configured to entersaid distal portion aperture and attach to said elongated member and thedistal fracture fragment to hold said distal portion of said elongatedmember to the distal fracture fragment, wherein said distal fixationmember has a first length and is sized and configured so that, inposition, it laterally extends through said elongated member distalaperture beyond the perimeter of said elongated member and across atleast a major portion of the radius in the metaphysis region; and atleast one proximal fixation member having a second length less than thedistal fixation member first length, a respective one for each of saidat least one proximal apertures, said proximal fixation memberconfigured to secure said proximal portion of said elongated fixationmember to the radius proximal to the fracture line, wherein, inposition, said elongated fixation member is configured and sized toreside within the radius such that both the opposing distal and proximalportions reside within the natural pre-injury bounds of the radius ofthe patient, and wherein said distal fixation member and said at leastone proximal fixation member are configured and sized as implants thatreside internally in the patient.
 24. A device according to claim 23,wherein said elongated fixation member has a curvilinear profile with anarcuate portion that substantially corresponds to the contour of theshape of the perimeter of the radius in the metaphysis region, saidcurvilinear profile including a distal curve portion at said distalportion of said elongated fixation member, said distal curve portionadapted to reside within the radial styloid region of the distal radiusproximate the articular joint surface.
 25. A device according to claim24, wherein said head is configured with an increased perimeter relativeto said elongated fixation member proximal portion, and wherein saidhead distal aperture angularly declines across the width of the elongatefixation member so that, in position, the lowermost portion of thedistal fixation member is located adjacent the ulna aspect.
 26. A deviceaccording to claim 25, wherein said distal end of said head isconfigured such that it declines across its width.
 27. A deviceaccording to claim 23, wherein said head is axially offset from thecenterline of the proximal portion of said elongate fixation member, andwherein said head flares to take on an increased width at said distalportion relative to said proximal portion.
 28. A device according toclaim 23, wherein said distal fixation member has opposing first andsecond end portions, the first end portion having a head that isconfigured to reside directly against said elongated fixation rod whenin position in a patient, and wherein, the distal fixation member issized and configured so that, in position, said opposing end portions ofthe distal fixation member reside inside the natural outer perimeter ofthe distal radius.
 29. A device according to claim 23, wherein elongatedfixation member proximal end portion has a smaller cross sectional thanthe distal portion.
 30. A device according to claim 29, wherein saidelongated fixation member proximal end portion is configured as atapered region.
 31. A device according to claim 23, wherein said atleast one proximal fixation member is configured to attach to saidelongated fixation member at a location which is proximal to thefracture line and the metaphysis region such that, in position, said atleast one proximal fixation member extends in serial order, through aportion of the radius shaft, through said proximal aperture in saidelongated fixation member, and then into an opposing portion of theradius shaft to thereby secure said proximal portion of said elongatedfixation member in position relative to the radius.
 32. A deviceaccording to claim 23, wherein said distal fixation member is secured tosaid elongated member such that, in position, said distal fixationmember is sized and configured to extend across a major portion of the,but less than the entire, width of the distal fracture fragment and/orthe distal radius bone proximate the articular joint surface.
 33. Adevice according to claim 32, wherein, in position, said distal fixationmember is sized and configured to extend across substantially the entirewidth of the distal fracture fragment from the radial to ulnar regionsand reside internally in the natural bounds of the distal radial bone toprovide support to the central and ulnar aspect of the distal radiusfragment.
 34. A device according to claim 33, wherein, in position, saiddistal fixation member laterally extends at least about 45 degrees awayfrom the axial direction defined by a line drawn through the center ofsaid proximal portion of said elongated member.
 35. A device accordingto claim 23, wherein said elongated member is configured in anassortment of incremental sizes ranging from about 2.5-4.5 inches longand about 2.5-4 mm in width.
 36. A device according to claim 23,wherein, in position, said distal fixation member is sized andconfigured to extend across a major portion of the width of the distalfracture fragment in the metaphysis region of the distal radius toreside within the bounds of the natural distal radius bone thereat. 37.A device according to claim 23, wherein said elongated member iscurvilinear and comprises a plurality of attachable interlockingsegments.
 38. A device according to claim 23, wherein the distalfixation member includes first and second opposing end portions, thefirst end portion having a head that is configured to reside directlyagainst the elongated member when in position.
 39. A device according toclaim 38, wherein the distal fixation member includes an intermediatethreaded portion between the first and second end portions, and whereinthe first end portion has a head that is configured to be received adistance into the distal aperture of the elongated member, the secondend portion being unthreaded for a length that is greater than thethreaded length of the intermediate portion.
 40. A device according toclaim 39, wherein said distal aperture comprises a threaded region that,in position, engages with the threaded intermediate portion of thedistal fixation member.